RANCHO MURIETA, CA (MPG) - Keeping Jackson Highway open during floods and wildfires is the goal of a Sacramento County resilience study that could shape how Rancho Murieta residents evacuate during future disasters. Residents got a second look at the project during two sparsely attended workshops on Jan. 24 at Rancho Murieta Community Church and on June 25 at The Villas Clubhouse, the second of three planned public meetings.

Sacramento County engineering manager Gary Gasperi said the study covers Jackson Highway (State Route 16) from Grant Line Road to Ione Road, including six signalized intersections. Funded by a Caltrans planning grant, the Rancho Murieta Resilience Plan will document how flooding and wildfire affect access to and from the community – particularly given its large population of residents age 60 and older – and identify improvements to keep emergency access and evacuation routes open during disasters.

Gasperi stressed that the effort is a planning study, not a construction project. Instead, it will provide the data, climate and traffic modeling, and project documentation needed to compete for future state and federal funding for improvements.

Hydrology consultant Joseph Albani of Sherwood Design Engineers said flood modeling confirmed Jackson Highway as Rancho Murieta’s primary evacuation route, with Dillard Road serving as the best alternate. However, both routes are vulnerable during major storms. Jackson Highway near Sloughhouse and Dillard Road north and south of the Cosumnes River could be overtopped by floodwaters, potentially cutting off both primary and backup access at about the same time.

Albani said possible improvements include larger culverts, replacing multiple small pipes with box culverts, raising sections of Jackson Highway, and strengthening embankments with riprap. The goal is to reduce flooding where possible and, when overtopping occurs, prevent washouts so that roads can reopen quickly.

During public comment, resident John Long said the analysis should also consider levee failures, noting that the breach of the Deer Creek levee was the key cause of widespread flooding three years ago. Albani said the team is considering adding levee-breach scenarios to the study, pending further project scope and county supervisor approval in July.

Wildfire specialist Carol Rice of Wildland Resource Management said the team is using updated vegetation maps, 25 years of weather data, and computer modeling to evaluate wildfire threats to Rancho Murieta and their impact on evacuation. The simulations focused on hot, dry northeast wind events and modeled three ignition points – two near Latrobe Road and a third near Clementia Circle – to show how rapidly fires could spread toward Rancho Murieta and Jackson Highway under worst-case conditions.

Rice said the scenarios allowed the traffic team to test whether residents could evacuate before fast-moving fires reached the community and Jackson Highway.

She recommended reducing roadside fire hazards along Jackson Highway by mowing grasses, removing hazardous trees, reducing ladder fuels, hardening power poles, and, where feasible, undergrounding utilities and adding highway turnouts for disabled vehicles and firefighting access.

Project facilitator Travis Shappell emphasized that the resilience study is limited to public road facilities and their impact on evacuation. It does not evaluate house-to-house firefighting tactics or Rancho Murieta’s internal water and hydrant systems.

Randy Johnson of DKS Associates said traffic simulations modeled every local street, gate and signal to evaluate how residents could evacuate under different wildfire scenarios. In phased evacuations, where only portions of Rancho Murieta are ordered to leave, he said traffic could clear the study area past Grant Line Road within the roughly two-hour departure window assumed by the model.

The greatest challenge comes during a worst-case, full-community evacuation involving about 5,700 vehicles, including traffic from a major event at the Equestrian Center. Johnson said the study tested several routing options using the Escuela emergency gate, Stonehouse Road and Scott Road in addition to the main gates. As with the other scenarios, Rancho Murieta North traffic would likely be directed west on Jackson Highway, while Rancho Murieta South traffic would head east, helping to split evacuation traffic in three directions.

 Even so, unmitigated conditions produced long backups on Jackson Highway, stretching from Grant Line and Sunrise toward Dillard and Rancho Murieta, adding nearly 1 hour and 45 minutes to the time it took to clear the community after residents began to evacuate.

Johnson said the greatest improvement would come from law enforcement officers manually directing traffic at key intersections. The model assumes that the California Highway Patrol and the Sacramento County Sheriff’s Office could staff the major signalized intersections within about 40 minutes.

Johnson said infrastructure upgrades would support law enforcement by helping to keep evacuation traffic moving. Proposed improvements include coordinated evacuation signal timing, backup power for traffic signals, cameras and traffic sensors, widening the Jackson Highway shoulders to serve as emergency lanes, and remote operation of the Escuela emergency gate from the guardhouse. He cautioned that Stonehouse Road may still need to be reserved for firefighting operations, so the emergency gate would be opened only when incident commanders determine it is safe.

In closing, project facilitator Travis Shappell said the Rancho Murieta Resilience Plan is about halfway complete. The presentation and a follow-up questionnaire will be posted online to gather additional public input. A third community meeting is planned for the fall to present proposed flood, wildfire and evacuation projects before the plan is finalized.

The study grew out of years of advocacy by the Rancho Murieta Regional Fire Safe Council, following the January 2023 storms, which exposed the community’s vulnerability when flooding cut off access. Retired traffic engineer John Long, who helped write the successful Caltrans grant application, worked with Fire Safe Council President Greg Pryor, council member John Merchant and then-Sacramento County Supervisor Sue Frost to secure the $400,000 planning grant that launched the project.